u/shadowphade

I am creating this post for a good giggle. (hopefully allowed)

been serving plumbing for 15 years and hear a lot of excuses or just things owners say. but what are some gems you have heard over your career that live rent free in your head?

C: what is wrong with it?

P: it is leaking and will need replacement.

C: can you tell me exactly what needs to replaced and what part i will need and where to get it so I can tell my handy man what he needs to do."

I am a plumber but this one has me stumped, i think i know the issue but i need to ask to make sure i don't charge for something the customer doesn't need.

They have a sewage pipe that when it discharges and empty's the pit. however, when the pump turns off there is a massive positive pressure and it pushes the water back into the pit at a very high rate. i have a replacement check valve ready to go as that is clearly gone. but what is causing such a downstream pressure that it launches the water back into the pit so fast?

context:

sewage pump installed on new addition of building. pit is vented. 2" abs, vertical rise 15' then horizontal run about 80-100'. one AAV installed 20' on horizontal run. then out to a stack. grade is good on this 2" line.

my thoughts:

the stack is not vented properly which is causing the increase pressure when pump fires. i was thinking of extending stack out external wall 20' above ground (tall warehouse). and potentially running a relief vent down 50' and tie in half way for extra air flow.

any advice would help.